1. Field of the Invention
The present invention relates to a process for producing a δ-aminopentadienoate compound (which may also be referred to as a δ-aminopentadienoate derivative).
2. Description of the Related Art
Processes for producing a δ-aminopentadienoate derivative have been known for a long time; for example, a process producing a δ-aminopentadienoate derivative via a dianil derivative has been disclosed (see, for example, U.S. Pat. Nos. 2,165,339, 2,186,608, and F. M. Hamer: The Cyanine Dyes and Related Compounds—The Chemistry of Heterocyclic Compounds Vol. 18, John Wiley & Sons, New York, London, 1964, Chapter XIII, p. 488-494). However, the reaction pathway of these processes is long, and the total yield is low.
A process has also been disclosed for producing a δ-aminopentadienoate derivative by reacting a streptocyanine derivative with a carbonyl compound in the presence of sodium hydride and triethylamine (see, for example, Tetrahedron Letters, vol. 21, p. 3,155 (1980)), but the sodium hydride used in this process is flammable and thus not suited for industrial purposes; furthermore, the yield is low.
As a production process overcoming these problems, a process that involves reacting a streptocyanine derivative with a carbonyl compound in the presence of a safe organic base has been disclosed (see, for example, Japanese Patent Application Laid-Open (JP-A) No. 2003-277349). In this process, however, an acetate derivative is used, and when the number of carbon atoms in an alkyl group of the ester is large (the number of carbons is 8 or more), the reactivity is lowered, resulting in a lower yield, and thus there is a demand for a process for production giving a high yield even with an alkyl group having a high number of carbon atoms.